In the conventional practice, the optical disk or the magnetic disk used as the signal recording medium of the recording and/or reproducing apparatus is contained in a cartridge and attached to the recording and/or reproducing apparatus as it is contained in the cartridge, thereby to protect the signal recording surface. A disk cartridge consisting of the cartridge and the disk contained therein is provided on the upper and lower sides thereof with a pickup device, such as an optical pickup device, adapted for reading or writing information signals for recording and/or reproduction. The disk cartridge is also provided with a slidable shutter for closing the apertures except when it is attached to the recording and/or reproducing apparatus, in order to prevent dust deposition on or injury to the disk contained in the cartridge.
For this reason, the recording and/or reproducing apparatus such as the disk player, making use of this type of the disk cartridge, is provided with a shutter opening and closing device.
It will be noted that, in the recording and/or reproducing apparatus making use of the aforementioned disk cartridge as the signal recording medium, reading or writing of the information signals becomes possible only when the disk cartridge is correctly inserted into the apparatus, the shutter is actuated by the shutter opening and closing device to open the signal read and write apertures, and the pickup device confronts the disk through these apertures. Reading or writing the information signal becomes impossible when the disk cartridge is attached in the recording and/or reproducing apparatus without the shutter being completely opened by the shutter opening and closing device. In a disk cartridge wherein insertion openings for the disk table of the disk rotation drive device and the pressor for pressing and supporting the disk against the disk table are formed contiguously to the signal read or write apertures so as to be covered by the shutter, it becomes impossible to chuck the disk contained in the cartridge to the disk rotation drive unit for driving the disk into rotation, unless the shutter is opened completely.
It is therefore an object of the present invention to provide a shutter opening and closing device that enabled the shutter to be opened only when the disk cartridge is inserted correctly, while also enabling the disk cartridge to be attached in position in the recording and/or reproducing apparatus when the shutter is opened completely, and a disk cartridge having a shutter that is opened and closed by the shutter opening and closing device.
It is another object of the present invention to prevent improper insertion or attachment of the disk cartridge for protecting the disk cartridge, the pickup device provided in the recording and/or reproducing apparatus, the disk rotation drive device or the disk chucking mechanism.